Page "Vega" Paragraph 36

The inner boundary of the debris disk was estimated at 11 ″ ± 2 ″, or 70 – 102 AU.

The disk of dust is produced as radiation pressure from Vega pushes debris from collisions of larger objects outward.

However, continuous production of the amount of dust observed over the course of Vega's lifetime would require an enormous starting mass — estimated as hundreds of times the mass of Jupiter.

Hence it is more likely to have been produced as the result of a relatively recent breakup of a moderate-sized ( or larger ) comet or asteroid, which then further fragmented as the result of collisions between the smaller components and other bodies.

This dusty disk would be relatively young on the time scale of the star's age, and it will eventually be removed unless other collision events supply more dust.